U.S. Pat. No. 3,512,449 issued in the name of E. M. Stoner discloses a recoil-operated gun wherein each spent cartridge is ejected out of the gun as the bolt carrier nears its full recoil position. The bolt assembly includes an ejector rod whose forward end abuts against the base of a cartridge that has been extracted from the firing chamber. As the bolt carrier moves rearwardly the ejector rod strikes the front face of a spring-cushioned buffer, thereby causing the rod to push the cartridge out of the gun. When the gun is operating normally the explosions associated with gun firing give the bolt carrier a high velocity in the recoil direction; therefore the ejector rod is given sufficient impact by the buffer to satisfactorily eject the spent cartridge. However, when the gun fails to fire a round there is no recoil velocity. A manually-controlled charging mechanism is provided to achieve motion of the bolt carrier in the recoil direction. As shown in U.S. Pat. No. 3,512,449, the charging mechanism comprises a hand crank-operated sprocket for moving a chain along the path of the bolt carrier; the chain is connected to a puller that draws the bolt carrier rearwardly when the hand crank is turned. In an effort to provide greater velocity it has been proposed to substitute an electric motor for the hand crank. However, even when a motor is used the bolt carrier velocity does not approach that which is explosively achieved during normal gun firing. Therefore, ejection of unfired ammunition rounds is not completely reliable.
The present invention proposes an auxiliary striker arm arranged in the path of the ejector rod as the charging mechanism moves the bolt carrier rearwardly into engagement with the buffer. A spring-urged piston propels the striker arm forwardly to apply a hammer force on the rear end of the ejector rod, thus causing the rod to eject the unfired cartridge from the gun. The advantage of this arrangement is that the striker force is independent of the rearward velocity of the bolt carrier. Thus, the charging mechanism can be manually-operated or motor-operated at a relatively slow speed without adversely affecting the cartridge-ejecting function.